FIST THINGS FIRST: Mike Rupp is one player the Rangers are hoping can take over the role played by the pugnacious Brandon Prust, who signed with the Canadiens in the offseason. Photo: Bill Kostroun, Getty Images

If it’s true that ignorance is bliss, maybe that begins to explain why Kyle Okposo became so distraught last season.

The Islanders’ winger and alternate captain is arguably the smartest man in the locker room — and would be in just about any locker room — so when he returned from shoulder surgery last October and had scored two goals — in the same game — during his first two months, he began to beat himself up.

“I went through a really tough time,” he told The Post this week. “So I’m looking to avoid that mental difficulty.”

In doing so, Okposo spoke to a sports psychologist during the summer break and the lockout, and he’s hoping that come Saturday, when the Islanders open the season playing host to the Devils, that the pressure will not overwhelm him.

“You have to take it with a grain of salt,” Okposo said about his experience with the psychologist. “You still have to play. You get out of it what you want to. I took what I liked and disregarded some stuff I didn’t.”

Okposo, still only 24 years old, is entering his fifth year in the NHL. He signed a five-year, $15 million deal before last season, which surely hung over his head as the goal-less games continued to rack up.

“You can work on the physical side all day, but when you’re struggling and things aren’t going your way, you have to have some mental stability and mental strength to fall back on,” Okposo said. “That’s one thing I might have been lacking last year.”

One thing he can fall back on is the fact he ended the season netting nine goals in the final nine games, getting him over the 20-goal mark (24) for the first time in his career. Most of those goals came when he was on the top line with John Tavares and Matt Moulson, the same trio that opened camp skating together.

“I think in the start of last year, he had a lot on his mind, just to find his rhythm and find his balance again,” Tavares said. “To have shoulder surgery, it kept him out a long time, and it took him a full year to get back to the way we know he can play and the dominance he can bring.”

* The Islanders claimed 23-year-old defenseman Thomas Hickey off of waivers from the Kings. … D Lubomir Visnovsky was not allowed by the KHL to play in his scheduled game in Prague yesterday.